Enhanced oral bioavailability of calcium using bovine serum albumin microspheres

Effect of sex and food on the pharmacokinetics of different classes of BCS drugs in rats after cassette administration

The cassette dosing technique is employed in the drug discovery stage of non-clinical studies to obtain pharmacokinetic data from multiple drug candidates in a single experiment. The objective of the current investigation was to evaluate the effect of sex and food on the selected pharmacokinetic parameters of four biopharmaceutical classification system (BCS) drugs (BCS-I: propranolol, BCS-II: diclofenac, BCS-III: atenolol, and BCS-IV: acetazolamide) utilizing cassette dosing in male and female rats under fed and fasting conditions. Different animal groups were dosed intravenous (i.v) and oral at 1 and 10 mg/kg, respectively, in the form of cassette at a dose of 5 mL/kg. Blood samples were analyzed by liquid chromatography-tandem mass spectrometry. Pharmacokinetics parameters were calculated using Phoenix software version 8.1. A significant increase (p < 0.05) of the area under the plasma concentration-time (AUC_0-last) was observed for diclofenac and acetazolamide in females over males after i.v dosing. Additionally, acetazolamide showed greater instantaneous concentration at the time of dosing, and clearance in females (p < 0.05) compared to males after i.v administration. After oral dosing, propranolol exhibited significant variations (p < 0.05) in the maximum drug concentration (C_max), AUC_0-last, the volume of distribution (V_d), and bioavailability in females as compared to males under fed state. Diclofenac showed significant changes (p < 0.05) in AUC_0-last, and clearance (Cl) in females as compared to males under fasting and fed state. However, acetazolamide exhibited a significant enhancement (p < 0.05) in AUC_0-last, V_d, and Cl in fasting females than the males. The data here illustrates that there is an appreciable difference in AUC and C_max values exist in male and female rats under fed and fasting conditions administered with the cassette dosing of tested BCS class drugs.

Formulation and optimization of gastroretentive bilayer tablets of calcium carbonate using D-optimal mixture design

Gastroretentive bilayer tablets of calcium carbonate (CC) were developed using D-optimal mixture design. The effect of formulation factors such as levels of HPMC K100 M (X1), sodium bicarbonate (X2), and HPMC E15 LV (X3) on responses like floating lag time (R1) and release of CC at 1 h (R2) and 6 h (R3) was elucidated. The optimized formulations developed by numerical optimization technique were found to have short floating lag time (2.85 ± 0.98 min), minimum burst release (27.02 ± 1.18%), and controlled yet near complete release (88.98 ± 2.75%) at 6 h. In vivo radiographic studies in rabbits indicated that optimized batch displayed a mean gastric retention time (GRT) of 5.5 ± 1 h which was significantly prolonged (P < 0.05) compared to the conventional tablets that displayed a GRT of less than 1 h. The studies proved that the gastroretentive tablets can be a promising platform to improve bioavailability of nutrients having absorption window in upper gastrointestinal tract.

Calcium-siRNA Nanocomplexes Optimized by Bovine Serum Albumin Coating Can Achieve Convenient and Efficient siRNA Delivery for Periodontitis Therapy

Purpose

Reducing toxicity, immunogenicity, and costs of small interfering RNAs (siRNA) carrier materials are key goals for RNA interference (RNAi) technology transition from bench to bed. Recently, calcium ions (Ca²⁺) have garnered attention as a novel, alternative material for delivering siRNA to cells. However, the tolerance for Ca²⁺ concentration varies in different cell types, which has limited its applications in vivo. Bovine serum albumin (BSA) can bind to Ca²⁺ through chelation. Moreover, BSA is a favorable coating material for nanoparticles owing to its excellent biocompatibility. Therefore, we hypothesized that coating Ca²⁺-siRNA with BSA helps buffer Ca²⁺ toxicity in vivo.

Methods

BSA-Ca²⁺-siRNA nanoparticles were prepared, and the size, shape, encapsulation, and release efficiency were characterized using atomic force microscopy, scanning electronic microcopy, and gel electrophoresis. Binding nanoparticles were evaluated using attenuated total reflection-Fourier-transform infrared spectroscopy. The cellular uptake, intracellular release, cytotoxicity, and gene knockdown of nanoparticles were evaluated in periodontal ligament stem cells (PDLSCs) using laser-scanning confocal microscope, flow cytometry, and real-time quantitative polymerase chain reaction.

Results

BSA and Ca²⁺-siRNA could form a stable nano-scale complex (~140 nm in diameter). The nanocomplexes could maintain siRNA release for more than 1 week in neutral phosphate-buffered saline (PBS) and could induce accelerated degradation in acidic PBS (pH 5.0). The nanoparticles were taken up by the cells, primarily through macropinocytosis, and were then released intracellularly through the acidification of endosomes/lysosomes. Importantly, the BSA-Ca²⁺ carrier had high transfection efficiency and biocompatibility both in vitro and in vivo. To demonstrate the therapeutic potential of our BSA coating-optimized Ca²⁺-siRNA technology, we showed that BSA-Ca²⁺-siWWP1 complexes strongly enhanced the osteogenic differentiation of inflammatory PDLSCs.

Conclusion

BSA-Ca²⁺ could potentially be used for siRNA delivery, which is not only highly efficient and cost-effective but also biocompatible to host tissues owing to the BSA coating.

The Beneficial Effect of Boswellic Acid on Bone Metabolism and Possible Mechanisms of Action in Experimental Osteoporosis

Estrogen is instrumental in the pathological process of osteoporosis because a deficiency of this hormone increases the release of bone-resorbing cytokines. Acetyl-11-keto-β-boswellic acid (AKBA), a constituent from Boswellia serrata, has an anti-inflammatory effect by inhibiting tumor necrosis factor-α (TNF-α) expression, which leads to a decline in receptor activator of nuclear factor-kappa B (NF-κB) ligand, and consequently, a reduction in osteoclast activity. Hence, AKBA may be beneficial against bone loss during osteoporosis. Therefore, the current study intended to evaluate the beneficial effects of AKBA in ovariectomy-induced osteoporosis and to investigate its mechanism of action. Sham-operation or ovariectomy female Sprague Dawley rats were used for evaluating the antiosteoporotic effect of AKBA in this study. AKBA (35 mg/kg, p.o.) and estradiol (0.05 mg/kg, i.m.) were administered for 42 days. At the end of the experiment, body and uterus weights, serum and urine calcium and phosphorus, serum alkaline phosphatase, and urinary creatinine levels, besides serum levels of NF-κB and TNF-α were determined. Weight, length, thickness, hardness, calcium content, as well as the bone mineral density of femur bone and lumbar vertebra were measured. A histopathological examination was also carried out. AKBA ameliorated all tested parameters and restored a normal histological structure. Thus, AKBA showed good antiosteoporotic activity, which may be mediated through its suppression of the NF-κB-induced TNF-α signaling pathway.

Development of Asialoglycoprotein Receptor-Targeted Nanoparticles for Selective Delivery of Gemcitabine to Hepatocellular Carcinoma

Selective targeting of anticancer drugs to the tumor site is beneficial in the pharmacotherapy of hepatocellular carcinoma (HCC). This study evaluated the prospective of galactosylated chitosan nanoparticles as a liver-specific carrier to improve the therapeutic efficacy of gemcitabine in HCC by targeting asialoglycoprotein receptors expressed on hepatocytes. Nanoparticles were formulated (G1–G5) by an ionic gelation method and evaluated for various physicochemical characteristics. Targeting efficacy of formulation G4 was evaluated in rats. Physicochemical characteristics exhibited by nanoparticles were optimal for administering and targeting gemcitabine effectively to the liver. The biphasic release behavior observed with G4 can provide higher drug concentration and extend the pharmacotherapy in the liver target site. Rapid plasma clearance of gemcitabine (70% in 30 min) from G4 was noticed in rats with HCC as compared to pure drug (p < 0.05). Higher uptake of gemcitabine predominantly by HCC (64% of administered dose; p < 0.0001) demonstrated excellent liver targeting by G4, while mitigating systemic toxicity. Morphological, biochemical, and histopathological examination as well as blood levels of the tumor marker, alpha-fetoprotein, in rats confirmed the curative effect of G4. In conclusion, this study demonstrated site-specific delivery and enhanced in vivo anti-HCC efficacy of gemcitabine by G4, which could function as promising carrier in hepatoma.

Nanoemulsion Based Vehicle for Effective Ocular Delivery of Moxifloxacin Using Experimental Design and Pharmacokinetic Study in Rabbits

Nanoemulsion is one of the potential drug delivery strategies used in topical ocular therapy. The purpose of this study was to design and optimize a nanoemulsion-based system to improve therapeutic efficacy of moxifloxacin in ophthalmic delivery. Moxifloxacin nanoemulsions were prepared by testing their solubility in oil, surfactants, and cosurfactants. A pseudoternary phase diagram was constructed by titration technique and nanoemulsions were obtained with four component mixtures of Tween 80, Soluphor^® P, ethyl oleate and water. An experiment with simplex lattice design was conducted to assess the influence of formulation parameters in seven nanoemulsion formulations (MM1–MM7) containing moxifloxacin. Physicochemical characteristics and in vitro release of MM1–MM7 were examined and optimized formulation (MM3) was further evaluated for ex vivo permeation, antimicrobial activity, ocular irritation and stability. Drug pharmacokinetics in rabbit aqueous humor was assessed for MM3 and compared with conventional commercial eye drop formulation (control). MM3 exhibited complete drug release in 3 h by Higuchi diffusion controlled mechanism. Corneal steady state flux of MM3 (~32.01 µg/cm²/h) and control (~31.53 µg/cm²/h) were comparable. Ocular irritation study indicated good tolerance of MM3 and its safety for ophthalmic use. No significant changes were observed in the physicochemical properties of MM3 when stored in the refrigerator for 3 months. The greater aqueous humor concentration (C_max; 555.73 ± 133.34 ng/mL) and delayed T_max value (2 h) observed in MM3 suggest a reduced dosing frequency and increased therapeutic efficacy relative to control. The area under the aqueous humor concentration versus time curve (AUC_{0–8 h}) of MM3 (1859.76 ± 424.51 ng·h/mL) was ~2 fold higher (p < 0.0005) than the control, suggesting a significant improvement in aqueous humor bioavailability. Our findings suggest that optimized nanoemulsion (MM3) enhanced the therapeutic effect of moxifloxacin and can therefore be used as a safe and effective delivery vehicle for ophthalmic therapy.

Proniosomal gel for transdermal delivery of lornoxicam: optimization using factorial design and in vivo evaluation in rats

OBJECTIVE

Clinical utility of lornoxicam in oral therapy is primarily restricted by the low solubility and gastric adverse effects. This study evaluated the prospective of optimized proniosomal gel to improve the clinical efficacy of lornoxicam and compare with oral therapy.

METHODS

Proniosomes were formulated by coacervation phase separation technique using span 60, lecithin and cholesterol. A four-factor three-level Box-Behnken design was used to evaluate the effect of amount of four independent variables; span 60 (X₁), cholesterol (X₂), lecithin (X₃) and lornoxicam (X₄) on response variables; vesicle size (Y₁), entrapment efficiency (Y₂) and transdermal flux (Y₃). The selected proniosomal gel (F19) was characterized, and evaluated for the transdermal efficacy by ex vivo and in vivo experiments.

RESULTS

Optimization study signifies that amount of formulation components (span 60, cholesterol, lecithin and lornoxicam) influence the vesicle size, entrapment efficiency and/or transdermal flux. Optimized formulation F19 exhibited nano size with high entrapment efficiency, adequate zeta potential, greater transdermal flux and better stability (at refrigerated conditions). The entrapment of lornoxicam in the bilayers of proniosome vesicles was confirmed by differential scanning calorimeter. Release profile of F19 was distinct (p < 0.001) from gel prepared using hydroxypropyl methylcellulose (control) and displayed steady lornoxicam release by Fickian diffusion. Transdermal administration of F19 significantly inhibited the carrageenan induced hind-paw edema in rats as compared to oral lornoxicam group.

CONCLUSIONS

The data observed in this study demonstrated that the developed proniosomal gel (F19) improved the clinical efficacy of lornoxicam as compared to oral therapy. Graphical Abstract Proniosomal gel for transdermal delivery of lornoxicam: optimization using factorial design and in vivo evaluation in rats.

A novel pH-enzyme-dependent mesalamine colon-specific delivery system

The aim of the present study was to design a new pH–enzyme double-dependent mesalamine colon-specific delivery system. The drug release behaviors in vitro and pharmacokinetics and biodistribution in vivo were further evaluated. The mean particle diameters of mesalamine-coated microparticles were 312.2 µm. In vitro, a small amount of mesalamine was released in HCl at a pH of 1.2 and PBS medium at a pH of 7.4 for 5 hours, and 71% of the entrapped mesalamine was further released during the subsequent 20 hours of incubation. A greater area under the plasma concentration–time curve (AUC)_0–t was obtained for the coated microparticles (1.9-fold) compared to the suspensions group, which indicated that the encapsulated mesalamine had mostly been absorbed in rats over the period of 12 hours. The AUC_0–t of the coated microparticles in colon was 2.63-fold higher compared to the suspensions (P<0.05). Hence, mesalamine-coated microparticles are considered to maintain the drug concentration within target ranges for a long period of time.